2013 NOTES 185

First Nesting Records for the Short-eared Owl, Asio flammeus , on , : Evidence of Range Expansion to Arctic Islands in

CYNTHIA MARJORIE SMITH 1,2 , N ORMAN ANDREW LAWRENCE 1,3 , and ROSEMARY ANNE BUCK 1,3

1Parks Canada, of Canada, , Northwest Territories X0E 0Z0 Canada; e-mail: cyndi.smith @pc.gc.ca 2Current address: P.O. Box 70, Mountain View, Alberta T0K 1N0 Canada 3Current address: P.O. Box 5457, Haines Junction, Yukon Y0B 1L0 Canada

Smith, Cynthia M., Norman A. Lawrence, and Rosemary A. Buck. 2013. First nesting records for the Short-eared Owl, Asio flammeus , on Banks Island, Northwest Territories: evidence of range expansion to arctic islands in Canada. Canadian Field-Naturalist 127(2): 185–188. Two Short-eared Owl, Asio flammeus , nests were discovered in the summer of 2000 along the in Aulavik National Park of Canada on Banks Island, Northwest Territories. One other sighting of a Short-eared Owl suggests the possibility of a third breeding pair. These nests are the first confirmed breeding evidence from islands in the Canadian . Key Words: Short-eared Owl; Asio flammeus ; nest; range expansion; Aulavik National Park of Canada; Banks Island; Northwest Territories Short-eared Owls, Asio flammeus , are highly no ma - ming, with the body missing. The incubating female dic, following fluctuating food resources and frequently (Figure 2) did not leave the nest until we were within breeding and wintering where numbers of small mam - about 3 m. There were seven eggs in a nest bowl lined mals are particularly high (Wiggins et al. 2006). Short- with dried grasses and a few feathers (Figure 3). The eared Owls are known to breed in suitable habitat nest was in a low space between tundra hummocks on throughout Canada, with the exception of the Canadian the edge of a wet sedge meadow (Figure 2). There were Arctic Archipelago (Committee on the Status of Endan - two Common Eider ( Somateria mollissima ) nests with - gered Wildlife in Canada 2008*). Suitable habitat in the in 20 m of the Short-eared Owl nest. Arctic includes coastal estuaries, tundra with areas of The following morning (28 June), an Arctic Fox small willows and dense grasslands (Committee on the (Vulpes lagopus ) was observed hunting in the area for Status of Endangered Wildlife in Canada 2008*). about half an hour, and both adult Short-eared Owls Since the mid-1970s, a number of biological surveys harassed it during that time, constantly swooping at it. have listed species of birds for Banks Island, North - The Arctic Fox disappeared from sight, then came into west Territories (Wilkinson et al. 1977*; Zoltai et al. view again at the same time that a female Common 1980*; Henry and Mico 1997*), but none documented Eider flew to a nearby pond. A check of the nest later the presence of Short-eared Owls. Raptors include the the same day revealed that the Short-eared Owl was fairly common ( Bubo scandiacus ) and still incubating, but the nearest Common Eider nest Rough-legged Hawk ( Buteo lagopus ), the less common had been predated. The Short-eared Owl nest was not ( Falco peregrinus ), and the rare Gyr - checked again until August 10, at which time it was falcon ( Falco rusticolus ). In the summer of 2000, how - empty. Because we did not know the date on which the ever, Short-eared Owls were documented for the first female began incubating, and the fact that nestlings will time on Banks Island. move some ways from the nest as young as 14 –17 days of age (Committee on the Status of Endangered Wildlife Observations in Canada 2008*), we cannot say whether the nest was The first of two Short-eared Owl nests was discov - successful or not, although the timing makes it possible. ered on 25 June 2000 near Green Cabin on the Thomsen The second Short-eared Owl nest was discovered on River (73.236°N, 119.545°W) in Aulavik National Park 23 July 2000, approximately 4 km downstream of the of Canada (Figure 1) and reported to park authorities. confluence of the River and the Thomsen Riv - Green Cabin is a patrol/research cabin upstream of Dis - er (73.856°N, 119.854°W), also in Aulavik National section Creek. On 27 June, when we approached the Park. Two adults were observed, and there were four nest, the male flew off from a location about 100 m pink-to-downy young in the nest. On both 27 and 28 from the nest. A subsequent inspection of the site where July, a single adult was seen hunting in the meadows in the male had flown up from revealed the head of a lem - the area. Since only the female is known to incubate 186 THE CANADIAN FIELD -N ATURALIST Vol. 127

FIGURE 1. Location of the two Short-eared Owl, Asio flammeus , nests (black circles) and single observation (open circle) in Aulavik National Park of Canada, Banks Island, Northwest Territories, in June and July 2000; the observations by Reid et al. (2011) on Herschel Island, Yukon (black triangle); and the observation by Therrien (2010) on Bylot Island, Nunavut (black square). Dashed line shows northern limit of breeding range in Canada (Wiggins et al. 2006); question marks indicate possible breeding areas (Wiggins et al. 2006). Map adapted from Wiggins et al. (2006).

(Wiggins et al. 2006), we presume this was the male. It was periodically followed and dive-bombed by a Pomarine Jaeger ( Stercorarius pomarinus ). This nest was ap proximately 70 km north of the nest near Green Cabin. On 2 July 2000, an adult was observed flying across the Thomsen River, between White Sand Creek and Shoran Lake (73.436°N, 119.688°W). Because of the distance from the Green Cabin nest (23 km) and the Muskox River nest (47 km), this observation might indicate the presence of a third breeding pair of Short- eared Owls. Holt (1992) reported territory sizes of up to 242 ha in various studies. In 2000, we also observed the following species for FIGURE 2. Short-eared Owl, Asio flammeus , female on nest the first time on Banks Island, near the community of (circle) near Green Cabin, Aulavik National Park of Sachs Harbour (71.986°N, 125.250°W): Merlin ( Falco Canada, Banks Island, Northwest Territories, 27 June columbarius ), Yellow-rumped Warbler ( Setophaga 2000. Photo: C. M. Smith . 2013 NOTES 187

cor onata ), Chipping Sparrow ( Spizella passerina ) albicollis ) (June 22). All four species were from 400- (June 11), and White-throated Sparrow ( Zonotrichia 750 km farther north than their known breeding ranges.

FIGURE 3. Short-eared Owl, Asio flammeus , nest near Green Cabin, Aulavik National Park of Canada, Banks Island, North - west Territories, with seven eggs, 27 June 2000. Photo: C. M. Smith.

Discussion biological responses is that the ranges of many species The observations reported here confirm breeding by of plants and animals are expanding northward Short-eared Owls in the Canadian Arctic Archipelago, (Thomas and Lennon 1999; Intergovernmental Panel over 500 km north of the mainland. Along with the on Climate Change 2001; Parmesan and Yohe 2003; three nests documented on Herschel Island, Yukon, in Brommer et al. 2012). The observations of the Merlin 2007 and 2008 (Reid et al. 2011) and territorial behav - and three passerines for the first time on Banks Island iour observed on Bylot Island, Nunavut, in 2008 (Ther - support the hypothesis that climate change enabled the rien 2010), these observations may provide evidence of range expansion of the Short-eared Owl. northerly range expansion by this species. It is also The Short-eared Owl is listed under the federal possible that Short-eared Owls have been breeding on Species at Risk Act as a species of “special concern” the islands for decades, but limited survey effort meant because of population declines attributed to habitat they were undetected. These may also have been extra- conversion/degradation on both the wintering and the limital breeding episodes in response to high numbers breeding grounds (Committee on the Status of Endan - of prey (Pitelka et al. 1955; Reid et al. 2011), mainly gered Wildlife in Canada 2008*). It is unknown to what Nearctic Brown Lemmings ( Lemmus trimucronatus ) extent range expansion in the islands in the Arctic might and Northern Collared Lemmings ( Dicrostonyx groen - compensate for this loss. landicus ). In 2000, twice as many lemming nests were observed on monitoring plots near Green Cabin as in Acknowledgements 1999 (Lawrence 2000*). We thank Marianne Douglas and John Smol, who If this is a range expansion, it may be related to cli - discovered the Green Cabin nest and reported it to the matic factors. A rise of 2–3 Celsius degrees in mean an - authors. We thank Peter Achuff and two anonymous nual temperature has been observed over the past 50 reviewers for commenting on earlier drafts of this years in the western and central Canadian Arctic (Zhang manuscript. et al. 2000; Furgal and Prowse 2008), and one of the 188 THE CANADIAN FIELD -N ATURALIST Vol. 127

Documents Cited (marked * in text) Holt, D. W. 1992. Notes on Short-eared Owl ( Asio flammeus ) Committee on the Status of Endangered Wildlife in Cana - nest sites, reproduction, and territory sizes in coastal Mas - da (COSEWIC). 2008. COSEWIC assessment and update sachusetts. Canadian Field-Naturalist 106: 352-356. status report on the Short-eared Owl Asio flammeus in Intergovernmental Panel on Climate Change (IPCC). Canada. Committee on the Status of Endangered Wildlife 2001. Climate change 2001: Impacts, adaptation, and vul - in Canada, Ottawa, Ontario. http://www.sararegistry.gc.ca nerability. Edited by J. J. McCarthy, O. F. Canziani, N. A. /virtual_sara/files/cosewic/sr_shorteared_owl_0808_e.pdf. Leary, D. J. Dokken, and K. S. White. Contribution of Henry, J. D., and M. Mico. 1997. The birds of Aulavik Na- Working Group II to the Third Assessment Report of the tional Park, Banks Island, Northwest Territories, Canada. Intergovernmental Panel on Climate Change. Published for Unpublished report. , Inuvik, North West Ter - the Intergovernmental Panel on Climate Change by Cam - ritories. http://www.taiga.net/reports/aulavikbirds/index bridge University Press, Cambridge, U.K. .html. Parmesan, C., and G. Yohe. 2003. A globally coherent finger - Lawrence, A. 2000. Lemming monitoring, Aulavik National print of climate change impacts across natural systems. Park, 2000. Unpublished report. Parks Canada, Inuvik, Nature 421: 37. North West Territories. Pitelka, F. A., P. Q. Tomich, and G. W. Treichel. 1955. Wilkinson, P. F., C. G. Hickey, S. Skaggs, H. Sherwood, Breeding behavior of jaegers and owls near Barrow, Alaska. R. W. Howe, and R. Dawe. 1977. A biological and archae - Condor 57: 3 –18. ological reconnaissance in north-central Banks Island, Reid, D. G., F. I. Doyle, A. J. Kenney, and C. J. Krebs. 2011 . Northwest Territories, July –August 1977. Department of Some observations of Short-eared Owl, Asio flammeus , Indian Affairs and Northern Development, Montreal, Que - ecology on arctic tundra, Yukon, Canada. Canadian Field- bec. Naturalist 125 (4): 307 –315. Zoltai, S. C., D. J. Karasiuk, and G. W. Scotter. 1980. A nat - Therrien, J-F. 2010. Territorial behavior of Short-eared Owls, ural resource survey of the Thomsen River area, Banks Asio flammeus , at more than 1000 km north of their current Island, North West Territories. Unpublished report prepared breeding range in northeastern Canada: evidence of range for Parks Canada by the Canadian Wildlife Service. Cana - expansion? Canadian Field-Naturalist 124 (1): 58 –60. dian Wildlife Service, Edmonton, Alberta. Thomas, C. D., and J. J. Lennon. 1999. Birds extend their ranges northwards. Nature 399: 213. Literature Cited Wiggins, D. A., D. W. Holt, and S. M. Leasure. 2006. Brommer, J. E., A. Lehikoinen, and J. Valkama. 2012. Short-eared Owl ( Asio flammeus ). Revised. No. 62 in The The breeding ranges of central European and Arctic bird Birds of . Edited by A. Poole. Cornell Lab - species move poleward. PLoS ONE 7: e43648.doi:10 oratory of Ornithology, Ithaca, New York. http://bna.birds .1371/journal.pone.0043648. .cornell.edu/bna/species/062. Furgal, C., and D. Prowse. 2008. Northern Canada. Pages Zhang, X., L. A. Vincent, W. E. Hogg, and A. Niitsoo. 2000 . 57-118 in From Impacts to Adaptation: Canada in a Temperature and precipitation trends in Canada during the Changing Climate 2007. Edited by D. S. Lemmen, F. J. 20th century. Atmosphere-Ocean 38(3): 395 –429. Warren, J. Lacroix, and E. Bush. Government of Canada, Ottawa, Ontario. Received 3 April 2013 Accepted 9 July 2013